Passive vs active in Scott B's words

[smgreen20]

This is what Scott Buwalda said about passive xovers. I do realize that his mid/upper line speakers are to be ran active, BUT this guy is also the top authority right now in SQ set ups and speakers.

"Passive crossovers are of the devil.

Seriously though, there is no good, defensible reason to use passive crossovers. Insertion losses, odd-order phase shift, damping factor dropping to zero on amplifiers, no flexibility, and the list goes on.

Passive crossovers will (hopefully) someday be the cassette tape of this industry. Only the really old school guys continuing to dabble with them..."

Just thought I'd share this. Here's the thread in which he states this.

http://www.buwaldahybrids.com/phpBB3/vi ... f=6&t=5364

[marko]

on that bombshell i'm throwing my crossblock in the trash bin

always 2 sides to the coin!

[Stryker]

I would love to run active but the amps i have do not have a X10 multiplier(most do not) and you then need a seperate processor as well as more RCA's. At some point i'll give it a go. i'm fine with how the RSd's sound using the supplied x-over's.
On a side note ti elites sound dam good using the massive x-over the made....

[dwnrodeo]

I've always been a fan of active myself. I know there is a thread in which Eric talks a lot about the engineering that goes into passive crossovers, but in car audio environments there are so many variables that can screw up a perfectly good passive crossover. Reflections, room gain, phasing, etc... Not to mention that there are so many places to mount mids and tweeters that how can you account for all of this in a passive crossover? How can engineers account for the different mounting positions? For example, a passive crossover has polarity markings for which way to wire the mids and tweeter so that the drivers are electronically in phase. Sure this works fine if the drivers are on axis facing the listener with no objects interfering, but how often is this a reality in a car? That's why we occasionally have to switch the polarity of one of the drivers to put them acoustically in phase, something that isn't designed into a passive crossover. Granted, you can overcome these issues and make it sound great, I just prefer active.

[marko]

^^^^^^^^^

Focal do exactly this, they design their speakers by tweeking them in a car. they are also designed to play off axis which for most is the usual scenario, no guess work involved just research.

i love active systems and had more active than passive set ups in the last 20 years but i honestly don't see how i could better my set up by going active.

[smgreen20]

they are also designed to play off axis...

Which is why I'd love to have a set of Focals. Someday I will, but a job has to come first, or a winning lottery ticket.

[kg1961]

I have had 2 set of high end kp2 focal and now have a high end set of boston pro's I love the way they sound out of the box
I just read this on the boston site:

The first point is that the typical active crossover does not allow nearly the flexibility of a passive design. The second point is that we often stagger or overlap the crossover points to achieve a flat response. The actual electrical crossover points for the woofer and tweeter however are generally asymmetric and different on all of the Boston components. Finding an active crossover that will allow you to adjust each of these points independently and tuning it correctly is going to be difficult but not impossible. Just as a note: designing a passive network takes our team of experienced engineers several months to complete.

You will get better performance from your system by paying more attention to the installation techniques and driver placement rather than pursuing the use of active crossovers. There is no substitute for proper speaker placement and solid installation.

[shawn k]

Oh boy here we go again!

Scott Buwalda is one of the top competitors of all time and he certainly knows what he's doing. I'm glad he shares the same views I do when it comes to the whole Passive vs active debate. Slightly makes it worth the time I had invested in the thread where Eric and I went back and forth.

smgreen20: thanks for opening up Pandora's box again LOL

[shawn k]

I've always been a fan of active myself. I know there is a thread in which Eric talks a lot about the engineering that goes into passive crossovers, but in car audio environments there are so many variables that can screw up a perfectly good passive crossover. Reflections, room gain, phasing, etc... Not to mention that there are so many places to mount mids and tweeters that how can you account for all of this in a passive crossover? How can engineers account for the different mounting positions? For example, a passive crossover has polarity markings for which way to wire the mids and tweeter so that the drivers are electronically in phase. Sure this works fine if the drivers are on axis facing the listener with no objects interfering, but how often is this a reality in a car? That's why we occasionally have to switch the polarity of one of the drivers to put them acoustically in phase, something that isn't designed into a passive crossover. Granted, you can overcome these issues and make it sound great, I just prefer active.

DUDE! Where the hell were you when I was in the debate with Eric??? Man it felt odd to be the only one trying to enlighten some of the benefits for going active.

[smgreen20]

smgreen20: thanks for opening up Pandora's box again LOL

Anytime, anytime....

Someone on his forum asked about the new PG line and if anyone had any "results" with them yet, so I went there to post the S400.4 review, as I already had the other 2 posted for them.

Just happened to see the question asked there at that time.

[kg1961]

i think doing this new or old everyone like there perfect sound play with what you like but that is why there will alway be other company sin everything in life .....
no one can always make the best of the best as we all can like something differnt..thats what make us ,us....
these are great points for both but shit do what you like turn it up and have fun!!!!!!!!!!!!!! get what you paid for and nothing else...lol[/list]

[Tiger]

Quoting a VERY valid point from that thread:

Passives can be fine - IF they're designed specifically for a given set of drivers IN GIVEN LOCATIONS in a given vehicle. Otherwise, they're hacks. How can one design a crossover when one doesn't even know how far apart the midwoofer and tweeter will be?

(I'll make a SLIGHT exception for coaxial/coincident/Dual Concentric drivers, because at least there the designer knows the relative spatial relationship between the drivers, and can make reasonable assumptions about listening axis, etc.)

Companies like them only because they keep their speakers from getting blown up to some degree.

SO true!

[Eric D]

I am not going to get into this, I lost the last argument.

But I will say this...

I have a Soundstream 705S in my truck right now. It is running bridged to my components. The mono channel runs my sub. I already ran separate wires from my tweeters and mids to the rear, as the passive crossovers sit right next to the amp (on the rear wall of the cab).

I have an Audiocontrol 24xs in a box, and the amp has its onboard crossover. I can un-bridge the amp and have 4 channels to play with instead of just 2. The wires to power the 24xs are already in place, as I used to have an EQL installed.

What will I gain by going active with this setup? Will I loose anything, and if so, what?

[Eric D]

Some additional information...

My components are Rockford FNQ1415 (first gen fanatic Q's). They have 24db slopes on the high and low pass. They have pretty simple crossovers, with no notch filters or other EQing (as far as I remember), so they are a great candidate for running actively.

I don't know the crossover points, but anyone with some older RF tech documentation can probably fill me in on that.

I just looked up the info on the 705S amp, and sadly it has only 12db slopes on the tweeter and midrange. Should I still try it, or do I need to use the AC 24xs instead?

My goal is to just unbolt the amp, flip the switches on the back of it, bolt it back in place, set the crossover frequencies, and then unhook the wires from the passive crossover and run them direct to the amp.

What other things do I need to do, or suggestions does anyone have?

[shawn k]

Why hey there Eric! I'm glad to see you are able to still kick it with us

So what will you gain and what will you loose?.. well it's hard to say really. There's a lot of variables that could sway a lot of things. So much of it has to do with your ability to tune and a good ear to decipher when something isn't right or could be improved. How many xover chips do you have for that 24xs? You will want a decent variety of them.

What will you lose (with proper tuning)? Worst case I would say hopefully just shear output.


What will you gain: Hopefully a more defined soundstage with better segregationg of instruments and vocals. Improved detail and dynamics. The ability to independently control each driver or at least the mid seperate from the tweet.

Ideally I would prefer a crossover with infinite adjustability and adjustable slopes. Some eq would be nice as well. This is why the processors available today are a great tool for something like this.

Give it a try and let us know how it goes

[Marcotah]

I'm pretty sure that active or passive depends much more on what are you using to power the system and the speaker that you are running than anyother thing...
For system that you are using digital processors, good quality amplifiers with a LOT (Means at least 5 to go 2 way with a mono channel for sub or 7 to go Three way with a mono channel to run tha subs) of channels and great power.
I would ask myself before goin active;
1 - Do I Have enough power to make it work? (In case of Elites ~100Wrms of clean power at least to each driver)
2 - Are my passive crosses that bad?
3 - What about the phase shift due to install issues (Mid too far from TW).
4 - Are my Speaker better for On-Axis or Off-Axis running?
5 - If will worth the wast of time if its doesn't work how you'd think. (Happens most of the time).

Making things short, I'd prefer runnin' a passive set feed by a 200Wrms of clean power (as PG good amps make) plus a sub channel than runnig it at 50~80Wrms/Driver on active.
Otherwise, if I had 150Wrms x 4 channels,what isn't that easy with small amps, I could try runnin' active.

We also have to consider that most of the people does NOT run your systems as factory recomendations.
I'd like to ask here, who of those that are running Elites is running at least with Pods with the tweeter near than 1 feet of the Mid-bass driver?
Should I say about signal changing when using active? Analog to Digital to Analog to Digital to...

I think this kind of discussion is nice, brings too much positive things, like knowledge improving.

[Marcotah]

Why hey there Eric! I'm glad to see you are able to still kick it with us

So what will you gain and what will you loose?.. well it's hard to say really. There's a lot of variables that could sway a lot of things. So much of it has to do with your ability to tune and a good ear to decipher when something isn't right or could be improved. How many xover chips do you have for that 24xs? You will want a decent variety of them.

What will you lose (with proper tuning)? Worst case I would say hopefully just shear output.

Give it a try and let us know how it goes

+1
+11
+111
+1111

[Eric D]

OK, I have one crossover chip for the 24xs, but it can be modified and I have piles of resistors to choose from.

So I take it I need to use the 24xs then, as the second order crossover in my amp is not good enough?

So I am going to loose output? That sucks, as the system is not really loud enough as it is. At full volume with the windows down I can't really enjoy it. This was never an issue with my MS1000TA in my car.

Since I am going to loose output, what would I need to add to get the system back to the same level of output as it is now?

My idea of what sounds good is not the same as most people (I like ruler flat setups, and that is what my current home setup is for example). However, I do have my RTA. So, I can RTA it the way it is now, and once I switch over to active the curve will get noticeably better, right?

I know if I have a variable crossover, I can tweak the settings a bit to get the RTA curve looking better. So, no matter what, the RTA curve will be better with active over passive, correct? (assuming it is setup correctly)

[Eric D]

One more thing, my head unit is a Kenwood KDC-X889. Will it be of any use for this? I currently have all its processing turned off, and just use one set of RCA cables. I do have a second set of RCAs I can run if need be, and I can make up a third set if that is also a requirement.

[shawn k]

OK, I have one crossover chip for the 24xs, but it can be modified and I have piles of resistors to choose from.

So I take it I need to use the 24xs then, as the second order crossover in my amp is not good enough?

You could probably get away with the crossover in the SS amp, but for an a/b comparison I would say stick with the 4th order slope.

So I am going to loose output? That sucks, as the system is not really loud enough as it is. At full volume with the windows down I can't really enjoy it. This was never an issue with my MS1000TA in my car.

Yes you will likely loose output Although I do not know the power capabilities for that particular amp so it's hard to say just how much, if any, you will loose.

My idea of what sounds good is not the same as most people (I like ruler flat setups, and that is what my current home setup is for example). However, I do have my RTA. So, I can RTA it the way it is now, and once I switch over to active the curve will get noticeably better, right?

This has nothing to do with an RTA nor a "ruler flat response". The ears are the judge here. The debate of Passive vs Active has to do with the ability of each system to "accurately" reproduce a recording. Flat tuned systems do not represent a "natural" or "accurate" experience. I'm not saying anyone is "wrong" for liking their music in a particualr way. Big bass systems and
or ruler flat systems may be pleasing to some and there's nothing wrong with that, but if one is not after a natural reproductiong then the debate between Passives and Actives is pointless

I know if I have a variable crossover, I can tweak the settings a bit to get the RTA curve looking better. So, no matter what, the RTA curve will be better with active over passive, correct? (assuming it is setup correctly)

Same response as above

[shawn k]

One more thing, my head unit is a Kenwood KDC-X889. Will it be of any use for this? I currently have all its processing turned off, and just use one set of RCA cables. I do have a second set of RCAs I can run if need be, and I can make up a third set if that is also a requirement.

I know the deck, but off the top of my head I can't remember what kind of internal processing it has. Probably not needed for this particualr comparison. Running an extra set of signal cables may be nice if only for the convenience of having a tweeter attenuation right there in front of you (via the fade control)

[dwnrodeo]

I've always been a fan of active myself. I know there is a thread in which Eric talks a lot about the engineering that goes into passive crossovers, but in car audio environments there are so many variables that can screw up a perfectly good passive crossover. Reflections, room gain, phasing, etc... Not to mention that there are so many places to mount mids and tweeters that how can you account for all of this in a passive crossover? How can engineers account for the different mounting positions? For example, a passive crossover has polarity markings for which way to wire the mids and tweeter so that the drivers are electronically in phase. Sure this works fine if the drivers are on axis facing the listener with no objects interfering, but how often is this a reality in a car? That's why we occasionally have to switch the polarity of one of the drivers to put them acoustically in phase, something that isn't designed into a passive crossover. Granted, you can overcome these issues and make it sound great, I just prefer active.

DUDE! Where the hell were you when I was in the debate with Eric??? Man it felt odd to be the only one trying to enlighten some of the benefits for going active.

Sorry. Sometimes I like to sit back and learn a bit before I decide to open my mouth. This time I felt compelled to share my opinions.

[Eric D]

This is now off topic, but I fail to see how an RTA does not have any use here, or anything to do with this.

I have a set of $2000 recording studio speakers. And for the record they are active, with separate internal amps (one on the tweeter, and one on the mid). I use them as specified by the manufacturer, by sitting 1 meter from them. They are about as ruler flat as you can get, until down around 80-100Hz, where the room starts to come into play. They sound great. Some of the best speakers I have ever owned. Countless others have agreed. Anyone I have had listen to them has liked them.

So what you are saying then is that if I shoot for this capability in my vehicle, it won't sound good?

We never know how a recording artist has EQed their final track. What we do know is the flatter the response the better the chance we will reproduce what the artist intended, considering they probably recorded the track on a ruler flat studio setup which they applied EQing to until they were satisfied.

If any system is not ruler flat, it is simply a guess as to what it should be. And who can determine if my guess or your guess, or the next guy's guess is closer to the "real" thing?

[smgreen20]

Even at a ruler flat response it's a guess as to how it should sound. When you RTA for ruler flat, you've undone half of what the producer has done. So even a ruler flat response is considered wrong to the recording.

It really does come down to what the listener likes. I prefer a flat response from 200 Hz on up, and a slight bump in the 20- 200 Hz area.

A 30+ year sound tech on the S&V mag forum uses a .5dB drop in response for every octave. After years of study, he has stated that this is the most natural sound and less fatiguing sound. That's not just by him, but of the 100s of people he's tested. It's a curve I'm going to set up for. I'm curious as to how good it sounds.

[shawn k]

Eric. For this particular comparison I think you are trying to be a little too technical. I do understand where you're comming from about flat response, but don't worry about it here. Remember the a/b comparison you did the write up for between the RF and PG amps? Treat this comparison in the same manor. I don't recall you applying any measurements or readings between the two amps, just purely listening to both to come to your conclusion. This is no different. You cannot "measure" a more difined soundstage, nor can you "measure" a more natural vocal presence. This is why I always say "trust your ears" and not the specs!

Systems utilizing passive xovers can still sound great! I have not tried to hide this. But so many of these xovers do not resemble a "flat" response (even tho the system sounds great).

IMO.. a system that has been tuned for a flat RTA response sounds horrible! This is why sound off competitors often use mutlitple eq's and/or intricate processors to enable them to have independant settings ie..one for a flat RTA reading and another for SQ (subjective listening). I assure you that none of these competitors would use their (RTA) setting for the SQ portion of the competition.

So put away the RTA and give it a go.. see how it sounds.. let us know